Arthur weinberg



UNITED STATES PATENT ()EEIcE.

ARTHUR \VEINBERG, OF MAINKUR, ASSIGNOR TO LEOPOLD CASSELLA & (30., OFFRANKFORT-ON-THE-MAIN, GERMANY.

BLUE DYE.

SPECIFICATION forming part of Letters Patent No. 469,329, dated February23, 1892. Application filed July 27,1891. Serial No. 400,867.(Speeimens.) Patented in France June 12. 1891. No. 211,821.

To 60% whom it may concern:

Be it known that I, ARTHUR WEINBERG, a citizen of the Empire of Germany,and a resident of Mainkur, near Frankfort-on-the-Maiu, have invented newand useful Improvements in the Production of Blue Dye-Stuffs, of whichthe following is a specification.

This invention has for its object the production of blue dye-stuffs. Apatent having the same object has been taken in France bearing thenumber 211,821, of June 12, 1891.

The known methods of producing thionine dye-stuffs from dimethylanilinecannot be used for the production of analogous derivatives ofdimethylotoluidine, because the latter cannot be transformed into anitroso compound.

The present specification relates to a process for obtaining thetoluthianines, of which the following is an example. The new dyestuffsare distinguished by their great intensity.

Example: 16.5 kilos of the nitrosamine of monamethyl (or ethyl)otoluidine are dis solved at about 5 centigrade in one hundred and fiftykilos of strong muriatic acid. After standing some hours the clearsolution, which then contains the hydrochlorate ofparanitrosomanomethyltoluidine, (NOC II NHC II is diluted with water andcooled with ice. It is reduced by means of thirteen kilos of zincdust.As soon as the liquid has become colorless, the free mineral acid isneutralized and 24.8 kilos of thiosulphate of soda and shortly afterwardten kilos of bichromate of potash are added. Then the solution of 17.2kilos of hydrochlorateof monomethylorthotoluidine is introduced. Theoxidation is performed by adding first one hundred and twenty kilos ofchloride of zinc, and then thirty kilos of hichromate of potash. Theliquid is heated to the boil. The coloring-matter is separated from theresidue, which contains the chrome. It forms small green crystals. Itdyes on cotton mordanted with tannic acid a pure blue.

Its chemical constitution is the following:

OH. a d T In this example, instead of monomethylotoluidine being used asthe second component, other amines may be employed, such as otoluidine,dimethylaniline, or diethylaniline.

Having now described the nature of my invention, what I claim as new,and desire to secure by Letters Patent, is-

The new dyestuff herein described, being a thionine derivative ofsecondary paratoluylenediamine, which is a dark-green crystalline powdereasily soluble in Water and in spirit, dissolving in alcohol with a bluecolor, which turns into red if caustic sodais added, and dissolving instrong sulphuric acid with a pure green shade.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ARTHUR VEINBERG.

\Vitnesses:

V ALVESTO S. IIooUE,

J EAN GRUND.

oorr'ections in Letters Patent No nimal/.9.

It is hereby certified that in Letters Patent No. 469,329, grantedFebruary 23, 1892, upon the application of Arthur Weinberg, of Mainkur,Germany, for an improvement in Blue Dyes, errors appear in the printedspecification requiring correction as follows: In line 15 the worddiinethylotoluidine should read dimethylorthotoZnicline in line 19 theword toluthianines should read tolnthionines in line 24: the wordmonamethyl should read monomethyl, same line the Word otoluidine shouldread orthotol'nidine in lines 28-29 the Wordparanitrosoinanoniethyltoluidine should readparanitrosomonomethyltolniciine; in lines 54-55 the wordmonomethylotoluidine. should read mononiethylorthotolnidine; and inlines 56-57 the the word otoluidine should read orthotolnidine; and thatthe Letters Patent should be read with these corrections therein thatthe same may conform to the record of the case in the Patent Office.

Signed, countersigned, and sealed this 24th day of May, A. D. 1892.

CYRUS BUSSEY, Assistant Secretary of the Interim".

[SEAL.]

Oountersigned:

N. 'L. FROTHINGHAM,

Acting Commissioner of Patents.

